The purpose of these studies is to investigate the regulation of metabolism in normal, diabetic, and adrenolectomized rats. Specifically to be studied are 1) the regulation of gluconeogenesis, glycogenolysis, transamination, and protein synthesis in isolated liver cells; 2) the role of insulin and other hormones in the regulations of lipolysis in the perifused fat cell system; and 3) the role of cyclic AMP and cyclic GMP in the control of glycogen metabolism and lipolysis in cardiac muscle. Glyconeogenesis will be assayed by measuring the incorporation of radiolabeled substrate (alanine and lactate) into glucose. Glycogenolysis and transamination will be assayed by measuring the incorporation of tritium from 5-H3 glucose amd 2-H3-alanine into T2O respectively. Cyclic mucleotide levels in tissues will be assayed by established competitive protein binding assays.